A mobile terminal typically needs to search for a radio cell to camp on when it is switched on and may for example also need to search for candidate radio cells for a potential or required handover during operation.
One of the most challenging cell search types is the initial cell search procedure which is carried out in frequency-unlocked mode, i.e. when the mobile terminal is not yet synchronized with the radio cell in terms of the radio frequency used by the radio cell. In this case, the cell searcher of the mobile terminal is responsible not only to find a suitable cell to camp on, but also to perform the initial frequency acquisition. In this stage, the modem of the mobile terminal typically experiences the worst case of frequency offset especially if, for example, there is a long period of inactivity between calibration during production of the mobile terminal and the first time it is switched on, or if the calibration still leaves a significant offset at least in some operating points, or if no calibration is performed
Accordingly, cell search procedures which are robust against frequency offsets are desirable.